compact
Hi there,
there is a simple script with example for counting rows and columns of a two-dimensional array.
<?php
$data = array(
"apples" =>
array("red", "yellow", "pineapples"),
"bananas" =>
array("small", "medium", "big"),
"vegs" =>
array("potatoes", "carrots", "onions")
);
$rows = count($data,0);
$cols = (count($data,1)/count($data,0))-1;
print "There are {$rows} rows and {$cols} columns in the table!";
?>
count
(PHP 4, PHP 5)
count — Cuenta los elementos de una matriz o propiedades de un objeto
Descripción
Devuelve el número de elementos en var , que típicamente es un array, porque cualquier otra cosa diferente de un objeto tendría sólo un elemento.
Para objetos, si tiene SPL, enlazarlo a count() implementando la interface Countable. La interface tiene exactamente un método, count(), el cual regresa el mismo valor que regresarí la función count().
Si var no es una matriz o un objeto, que tenga implementado la interface Countable, se regresará 1. Hay una excepción, si var es NULL, se regresará 0.
Note: El parámetro opcional mode está disponible desde PHP 4.2.0.
Si el parámetro opcional mode es iniciado a COUNT_RECURSIVE (o 1), count() contará recursivamente la matriz. Esto es útil particularmente para contar todos los elementos de una matriz multidimensional. El valor por defecto para mode es 0. count() no detecta recursión infinita.
Caution
count() puede regresar 0 para una variable que no ha sido inicializada, pero también regresa 0 para una variable que ha sido inicializada con una matriz vacía. Use isset() para probar si la variable ha sido definida.
Por favor vea la sección del manual sobre Array para una explicación más detallada de como son usadas e implementadas las matrices en PHP.
Example #1 Ejemplo
<?php
$a[0] = 1;
$a[1] = 3;
$a[2] = 5;
$result = count($a);
// $result == 3
$b[0] = 7;
$b[5] = 9;
$b[10] = 11;
$result = count($b);
// $result == 3
$result = count(null);
// $result == 0
$result = count(false);
// $result == 1
?>
Example #2 Ejemplo recursivo (PHP >= 4.2.0)
<?php
$food = array('fruits' => array('orange', 'banana', 'apple'),
'veggie' => array('carrot', 'collard', 'pea'));
// recursive count
echo count($food, COUNT_RECURSIVE); // output 8
// normal count
echo count($food); // output 2
?>
Vea también is_array(), isset(), and strlen().
add a note
User Contributed Notescount
jezdec at email dot cz
19-Apr-2009 11:42
19-Apr-2009 11:42
michael.debyl at gmail dot comz0r
16-Jul-2008 10:45
16-Jul-2008 10:45
There doesn't seem to be a succinct method already noted on this page for counting multidimensional array end nodes (Items in multidimensional arrays), so I thought this function might help somebody.
Nice and simple :)
<?php
function rcount ($array) {
$count = 0;
if (is_array($array)) {
foreach($array as $id=>$sub) {
if (!is_array($sub)) { $count++; }
else { $count = ($count + rcount($sub)); }
}
return $count;
}
return FALSE;
}
?>
analpaper{gmail}
04-Jul-2008 02:37
04-Jul-2008 02:37
I found useful this little function that detects if a array is multidimensional or not.
<?php
function array_is2D($array) {
return is_array($array) ? count($array)===count($array, COUNT_RECURSIVE) : -1;
}
?>
---
live2code
Anonymous
11-Jan-2008 09:20
11-Jan-2008 09:20
Here is an iterative soloution of danny's count_recursive function which might be more efficient due to the missing recursion
<?php
/**
* counts elements of an multidimensional array
*
* @param array $array Input Array
* @param int $limit dimensions that shall be considered (-1 means no limit )
* @return int counted elements
*/
function multicount ($array, $limit = -1)
{
$cnt = 0;
$limit = $limit > 0 ? (int) $limit : -1;
$arrs[] = $array;
for ($i=0; isset($arrs[$i]) && is_array($arrs[$i]); ++$i)
{
foreach ($arrs[$i] as $value)
{
if (!is_array($value) ) ++$cnt;
elseif( $limit==-1 || $limit>1 )
{
if( $limit>1 ) --$limit;
$arrs[] = $value;
}
}
}
return $cnt;
}
?>
atoi_monte at hotmail dot com
28-Jun-2007 09:10
28-Jun-2007 09:10
Please note: While SPL is compiled into PHP by default starting with PHP 5, the Countable interface is not available until 5.1
danny at dannymendel dot com
13-Jun-2007 08:14
13-Jun-2007 08:14
I actually find the following function more useful when it comes to multidimension arrays when you do not want all levels of the array tree.
// $limit is set to the number of recursions
<?php
function count_recursive ($array, $limit)
{
foreach ($array as $id => $_array)
{
if (is_array ($_array) && $limit > 0) $count += count_recursive ($_array, $limit - 1); else $count += 1;
}
return $count;
}
?>
yarolan at mail dot ru
26-Apr-2007 11:56
26-Apr-2007 11:56
NEVER USE IN CYCLES!
<?php
//size of $arr ~ 2000 elements
//wrong variant (Time exec ~ 19 sec)
for($i=0;$i<count($arr);$i++)
{
//...
}
//right variant(Time exec ~ 0.2 sec)
$arr_size=count($arr);
for($i=0;$i<$arr_size;$i++)
{
//...
}
?>
it was discovered experimentally.
Colin
03-Feb-2007 03:24
03-Feb-2007 03:24
<?php
// countValuesRecursive
// The goal of this function is to count non-false values of a multidimenional array
// This is useful in making a quick determination if a form sent any values
// If no values were sent I can simply return to the blank form rather than continuing to the validation of each input
// There are two limitations of the principle:
// 1. If you WANT to send FALSE, 0, '', or NULL as form values this function will not count those, thus not doing what's expected
// 2. This would create an endless loop on a form that has no required fields such as one where users can choose to recieve optional email subscriptions but where choosing none is also valid
function countValuesRecursive($array, $count = 0) {
// Cycle through the array
foreach ($array as $value) {
// Check if the value is an array
if (is_array($value)) {
// Cycle through deeper level
$count = countValuesRecursive($value, $count);
}
else {
// Check if the value is TRUE
if ($value) {
$count++;
}
}
}
// Return the count
return $count;
}
?>
alexandr at vladykin dot pp dot ru
08-Nov-2006 12:28
08-Nov-2006 12:28
My function returns the number of elements in array for multidimensional arrays subject to depth of array. (Almost COUNT_RECURSIVE, but you can point on which depth you want to plunge).
<?php
function getArrCount ($arr, $depth=1) {
if (!is_array($arr) || !$depth) return 0;
$res=count($arr);
foreach ($arr as $in_ar)
$res+=getArrCount($in_ar, $depth-1);
return $res;
}
?>
anil dot iitk at gmail dot com
26-Jan-2006 08:32
26-Jan-2006 08:32
<?php
$food = array('fruits' => array('orange', 'banana', 'apple'),
'veggie' => array('carrot', 'collard', 'pea'));
// recursive count
echo "<br>".count($food, COUNT_RECURSIVE); // output 8
function average($a){
return array_sum($a)/count($a) ;
}
$b = array(1,2,3,4,5,6,7,8,9);
echo "Average of array:".average($b);
?>
Scorch at netpix dot com
20-Dec-2005 01:59
20-Dec-2005 01:59
Be careful of recasting your variables, especially with database array returns:
<?php
$res = mysql_query("select * from blah") // a query that returns an empty set
$row = mysql_fetch_array($res); // get's 0 since there's no return
echo count($row); // echos 1 - since $row is not an array
echo $row[0]; // echos "", but casts $row as an array?
echo count($row); // echos 0 now
?>
Tom
01-Dec-2005 12:57
01-Dec-2005 12:57
You can find an average from an array using this and array_sum.
<?php
//array average( array input )
function average($input) {
return array_sum($input) / count($input);
}
?>
You can also do a method of form validation that involves putting all errors into an array and letting count() do the key part.
<?php
if(isset($_POST['submit'])) {
$errors = array();
if(empty($_POST['message'])) $errors[] = "Empty message field";
if(!preg_match('/[a-z0-9.]@[a-z0-9].[a-z]/i', $_POST['email']) {
$errors[] = "Bad email address";
}
if(count($errors) == 0) {
//process form...
}
}
?>
Fred D
18-Oct-2005 04:16
18-Oct-2005 04:16
The trim_text function was helpful, but it did not take account of the possibility of having nothing to trim which can sometimes happen if you are using this function in a loop through data. I've added a count function to deal with that possibility
<?php
function trim_text_elipse($text, $count){
//Create variable
$trimmed="";
//Remove double white space
$text = str_replace(" ", " ", $text);
//Turn the text into an array
$string = explode(" ", $text);
//Check to see how many words there are
$wordTotal = count($string);
//Check to see if there are more words than the $count variable
if($wordTotal > $count){
//Loop through adding words until the $count variable is reached
for ( $wordCounter = 0; $wordCounter <= $count; $wordCounter++ ){
$trimmed .= $string[$wordCounter];
//Check to and add space or finish with elipse
if ( $wordCounter < $count ){ $trimmed .= " "; }
else { $trimmed .= " …"; }
}
}else{
//Set value returned to the existing value
$trimmed =$text;
}
//Trim off any white space
$trimmed = trim($trimmed);
return $trimmed;
}
?>
david _at_ webgroup _dot_ org
13-Feb-2005 12:30
13-Feb-2005 12:30
While michael at htmlland dot net's code works, I believe it is better to use:
$extension=substr($file,strrpos($file,".")+1);
This doesn't incur the overhead of array handling. I haven't tested it for time functions, but it should work just as well and SHOULD be faster.
freefaler at gmail dot com
20-Nov-2004 01:01
20-Nov-2004 01:01
If you want to count only elements in the second level of 2D arrays.A close to mind note, useful for multidimentional arrays:
<?php
$food = array('fruits' => array('orange', 'banana', 'apple'),
'veggie' => array('carrot', 'collard','pea'));
// recursive count
echo count($food,COUNT_RECURSIVE); // output 8
// normal count
echo count($food); // output 2
// all the fruits and veggies
echo (count($food,COUNT_RECURSIVE)-count($food,0)); //output 6
?>
moazzam at ummah dot org
14-Oct-2004 11:59
14-Oct-2004 11:59
This is an obvious note, but I am writing it any way so other, who did may not have observed this, can take advantage of it too.
When running loops with count conditions, the code runs faster if you first assign the count() value to a variable and use that (instead of using count() directly in a loop condition.
To explain my point better, here is an example:
<?php
for ($i=0; $i<10000; $i++) {
$arr[] = $i;
}
$time11 = microtime_float();
$bf = "";
for ($i=0; $i<count($arr); $i++) {
$bf .= $arr[$i]."\n";
}
$time12 = microtime_float();
$time1 = $time12 - $time11;
print "First: ".$time1."\n";
$time21 = microtime_float();
$l = count($arr);
for ($i=0; $i<$l; $i++) {
$bf .= $arr[$i]."\n";
}
$time22 = microtime_float();
$time2 = $time22 - $time21;
print "Second: ".$time2."\n";
?>
The output from the code above is (when run many times):
First: 0.13001585006714
Second: 0.099159002304077
First: 0.12128901481628
Second: 0.079941987991333
First: 0.18690299987793
Second: 0.13346600532532
As you can see, the second method (which doesnt use count() directly in the loop) is faster than the first method (which uses count() directly in the loop).
BTW: I copied the microtime_float() function from one of the comments in the microtime() section. It just returns time with microseconds as float. Check comments in microtime() for more info.
michael at htmlland dot net
04-Jun-2004 05:30
04-Jun-2004 05:30
I have found on upload scripts or on file manipulation scripts that people can trick a classic file type filter:
example:
<?php
$filename="bob.jpg.wav";
$bits= explode(".",$filename);
$extention= $bits[1];
if($extention == "jpg"){ echo"Not correct"; exit; }
?>
This returns the filename extention as jpg not wav.
One way to change this is to use count() :
example:
<?php
$filename="bob.jpg.wav";
$bits= explode(".",$filename);
$extention= $bits[count($bits) - 1];
if($extention == "jpg"){ echo "Not correct"; exit; }
?>
This returns the filename extention as wav not jpg.
rolandfoxx at yahoo dot com
31-Mar-2004 12:13
31-Mar-2004 12:13
As an addition, any of the array manipulation functions can likewise get count to once again return 0:
<?php
$a = array();
print(count($a)); // prints 0
$a[0] = "foo";
array_shift($a);
print(count($a)); //prints 0
$a[0] = "bar";
array_splice($a, 0, 1);
print(count($a)); //prints 0
?>
admin at lft-muenchen dot de
12-Mar-2003 12:18
12-Mar-2003 12:18
Note:
<?php
print (strlen($a)); // will print 0
$a="";
print (strlen($a)); // will print 1
$a=null;
print (strlen($a)); // will print 1
$a=array();
print (strlen($a)); // will print 0
?>
you can only get an array back to size 0 by using the array() command, not by just setting it to "" or null.
simon at invalid dot com
20-Aug-2002 07:40
20-Aug-2002 07:40
Reminder for using count():
<?php
$ary = array(null, "a", "b", null);
echo count($ary); // count: 4
$ary[10] = "c";
echo count($ary); // count: 5
$ary[15] = null;
echo count($ary); // count: 6
?>
=> NULL is seen as an element in count()
Count 2D array:
<?php
$a2Dary = array(array("a", "b") , array(), "v");
echo count($a2Dary); // count: 3
echo count($a2Dary[0]); //count 2
echo count($a2Dary[1]); // count: 0
echo count($a2Dary[2]); // count: 1
?>
Hope can help you
webmaster at NOSPAMtrafficg dot com
26-Apr-2002 10:48
26-Apr-2002 10:48
Counting a multi-dimentional array
test array
<?php
$settings[0][0] = 128;
$settings[0][1] = 256;
$settings[0][2] = 384;
$settings[0][3] = 512;
$settings[0][4] = 1024;
$settings[0][5] = 2048;
$settings[1][0] = 1024;
$settings[1][1] = 2048;
$settings[1][2] = 3072;
$settings[1][3] = 4096;
count($settings) // returns 2
count($settings[0]) // returns 6
count($settings[1]) // returns 4
?>
kanareykin at denison dot edu
26-Mar-2001 09:13
26-Mar-2001 09:13
Here's how to count non-empty elements
in an array of any dimension. Hope
it will be useful for somebody.
<?php
// recursively count all non-empty elements
// in array of any dimension or mixed - i.e.
// array('1' => 2, '2' => array('1' => 3, '2' => 4))
function count_all($arg)
{
// skip if argument is empty
if ($arg) {
// not an array, return 1 (base case)
if(!is_array($arg))
return 1;
// else call recursively for all elements $arg
foreach($arg as $key => $val)
$count += count_all($val);
return $count;
}
}
?>
martin at complinet dot com
30-Nov-2000 12:31
30-Nov-2000 12:31
The count function does not ignore null values in an array. To achieve this use this function.
<?php
function xcount($array) {
while (list($key, $value) = each($array)) {
if ($value) {
$count++;
}
}
return $count;
}
?>
jmcastagnetto at php dot net
04-Sep-2000 07:30
04-Sep-2000 07:30
If you want to disambiguate if a variable contains an array w/ only one element, just us is_array() or gettype()
legobuff at hotmail dot com
02-Feb-2000 06:43
02-Feb-2000 06:43
This is taken from sganer@expio.co.nz comments on the sizeof() function:
If some elements in your array are not set, then sizeof() and count() will not return the index of the last element, but will return the number of set elements. To find the index of the last element in the array:
end($yourArray);
$index = key($yourArray);
... Where $yourArray is the array you want to find the last index ($index) of.